Lanos valtouzlet reszvenytarsasag



E. SCHIMANEK CARBURETOR Feb. 3, 1931.

Original Filed March 1927 Patented Feb. 3, 1931 UNITED STATES PATENT OFFICE EMIL SCHIMNEK, OF BUDAPEST; HUNGARY, ASSIGNOR TO HERMES MAG-YAR ALTA- LANOS VALTOUZLET RESZVENYTARSASAG, OF BUDAPEST, HUNGARY, A LIMITED COMP.ANY OF HUNGARY CABBURETOR Original application filed-March 16, 1927, Serial No. 175,872, and in Hungary Septem ber 11, 1926. Divided and this application filed February 14, 1929. Serial No. 339,930.

This invention relates to a carburetor of the kind in which the whole amount of air drawn through the carburetor is utilized for primary and secondary mixing purposes, and a piston is provided for regulating the secondary mixture and controlled by the negative pressure prevailing at the secondary mixing point, which piston has an internal passage for conveyingthe primary mixture to said secondary mixing point; said piston maintaining the negative pressure constant at the said point irrespective of the variations in the number of revolutions of the engine fed by the carburetor. More particularly the invention relates to'carburetors of this kind as described in my copending application Serial No. 175,872, filed March 16, 1927, which matured into Patent No. 1,778,868 issued Oct. 21, 1930, of which the present case is a division, according to which an atomizing tube is rigidly connected to the piston providing an internal mixture passage-which opens at its upper end through the side wallof the piston.

The invention consists substantially in the combination of an atomizing ,or primary mixing tube connected to a vertically adjustable fioating piston controlling the free cross section of the passage of the air for final atomizing or secondary mixing of the atomized-primary mixture, with means for turnretor, and 5 the outlet opening for the sec-. 'ondary mixture which is in communication with the inductionpipe 32 of the engine, said ipe having a throttle valve. 8. 3 is a float ing piston which constitutes the regulating member and which isvertically movable in the cylinder 4.

- The outlet opening 5' is formed in the wall of the cylinder 4 and is uncovered as the piston 3 rises. 17 is the float chamber containing the fuel 31 admitted through a valve (not shown) and maintained in known manner at a constant level by a float 18. The piston 3 is equipped with a hollow rod 10 that extends downward from it into the float chamher; and into the fuel opening 21 at the lower end of this rod projects a tapered needle 22 which closes said opening 21 in accordance with the position of the piston. At the point 14 where the primary mixture of fuel and air (produced as hereinafter described) passes through the opening 5 into the mixing chamber 7, said mixture is mixed with the air entering said chamber in the direction of the arrow 37 and forms a secondary mixture, the first mixture being the primary one. The negative pressure prevailing at the point 14 is transmitted through an opening 13 formed in apartition provided in the piston to the space 15 above the piston, so that the said pressure effects the regulation by moving the piston when, for instance, owing tothe increased number of revolutions of the engine,

the negative pressure is intensified; that is to say, overcomes theweight of the piston and the action of its spring, if any. I

In order that the negative pressure acting on the piston shall be as small as possible, while pronounced'negative pressure is avail able for atomizing purposes, a Venturi tube 42 is provided in the lower part of the hollow piston rod 10. A nozzle 19 projects from the lower aperture or fuel inlet 21 of the rod 10 into the bottom opening 20 of the Venturi tube 42. 12-is a slot in the side wall of-rod 10 to admit air from the casing 1 in the direction of. arrow 38 to form the primary mixture at the nozzle 19. 43 is a partition separating the spaces in the hollow rod 10 below the slot 12 from the up er part ofthe hollow rod. Another slot 11 Formed in the wall of the rod 10 above the partition 43 may be provided to admit additional air, as shown by the arrow 39,'into the space within said rod above the upper mouth of the Venturi tube 42. The lower cylindrical part of the rod 10 slides in a tubular upward projection or.

cylinder 23 of the top of the float chamber 17 24 is an aperture or recess in said cyline der 23.

The lower end of the Venturi tube 42 projects downward substantially to the level of the liquid in the fuel chamber 17, so that while the engine is at rest and the piston 3 in its lowest position. the upper end of the nozzle 19 is brought below the level of the liquid and fuel is collected in the lower end of the rod 10 in the cup 16 formed around said nozzle up to the level XX, owing to which a richer mixture is available for starting.

Owing to the provision of a skirt 9 depending from the lower. edge 33 of the piston 3, the free cross-section of the opening 5 controlled by the piston 3 can be varied by rotating the piston about its axis, while the level of the piston remains invariable. For turning the piston 3 independently of its vertical movements, the piston is provided with an eccentrically-positioned vertical guide. pin 30 slidably engaging a correspondingly-arranged opening 29 in a disk 28 secured to a spindle 27 rotatably mounted in the hub 25 of the cover 26 of the cylinder 4 and provided at its outer end with a handle 31. The edge 40 of the skirt 9 (Fig. 2) moves to the position 40a, more or less to the left of the vertical edge 44 of the opening 5, the opening 41 remaining in any position 1414a within the area of the opening 5. In this way, while the open cross-sectional area of the fuel inlet 21 remains invariable, the cross-section represented by the hatched part 35 and by the double-hatched part 36 afforded between the edges 33 and 34 in the position 40 of the skirt 9 is reduced to the double-hatched part 36 in the position 40a of the skirt.

At the same time, however, the quantity of air utilized for atomization or primary mixing is varied because. owing to the cooperation of the air inlet slots 11 and 12 in the piston rod 10 with the aperture 24 of cylinder 23, the rotation of the piston 3 and the rod 10 secured to the same will bring a more or less greater portion ofv said slots into register with said aperture 24 (Fig. 3), resulting,

in consequence, in a greater or smaller quantity of air passing into the atomizer.

I claim as my invention 1 1. In a carburetor, a casing havingan air inlet at its lower portion and a mixture outlet at its upper portion; a floating piston movable vertically in the casing for dlrectly controlling the outlet; an atomizing tube rigidly connected to the piston to move therewith and providing an internal mixture passage which opens at its upper end through the said wall of the piston for communication with said outlet and has an air inlet at its lower end; a vertical guide member secured to the piston; a rotatably mounted member let at its upper portion; a mixing chamber adjacent to and communicating with said outlet, said casing providing therein an internal air space leading to said mixing chamber;

a fuel inlet within the casing; a verticallymoving, floating piston within the said casing for directly controlling the outlet; an atomizing tube rigidly connected to the piston to move therewith and providing an internal primary mixing passage which opens at its upper end through the wall of the piston for communication with the outlet and has an air inlet at its lower end, said piston act-' ing to control simultaneously the fuel inlet and the space leading to the mixing chamber; a vertical guide member secured to the piston; a rotatably-mounted member with which the vertical member is slidably engaged to turn the piston about its axis. independently of its vertical movements; and a depending skirt on the piston acting as a slide valve to control the said space leading to the mixing chamber; the said atomizing tube being slotted to provide communication between the primary mixing passage and the interior air space within the casing.

3. A carburetor, according to claim 2, in which a stationary cylinder is fixed within the casing, and the atomizing tube has secured to it a cup that fits rotatably within said stationary cylinder; said cylinder and cup being provided with registering openings.

4. A carburetor, according to claim 2, in which a stationary cylinder is fixed within the casing, and the atomizing tube has secured to it a cup that fits rotatably within said stationary cylinder; said cylinder and cup being provided with registering openings; and said cup having the fuel inlet arranged at itsbottom and projecting above the same.

In testimony whereof I hereunto atfix my signature.

EMIL SCI-IIMANEK. 

